Reactive Aggregate Distress

Description

Pattern or map cracking (crazing) on the PCC slab surface caused by reactive aggregates. Reactive aggregates are those that either expand or develop expansive by products when introduced to certain chemical compounds.

Figure 1: Severe crazing (alkali-silica reaction).

Problem

Roughness, an indication of poor aggregate – will eventually lead to PCC slab disintegration.

Possible Causes

This type of distress is indicative of poor aggregate qualities. Most commonly, it is a result of an alkali-aggregate reaction.

Repair

Partial depth patch for small areas of scaling or slab replacement for large areas of scaling.